Adhesive-backed pressure-sensitive tapes vary considerably in many respects, e.g., as to size, substrate or tape body material and construction, adhesive composition, and end-use applications, but apart from such diverse differences, it is recognized that substantially all adhesive tapes may be quantitatively and qualitatively evaluated according to their adhesion characteristics, particularly resistance to shear and peel forces, as a comparative measure of suitability for a designated end-use. Nevertheless, for many adhesive tapes, no accepted methodology or apparatus exists for systematically testing the adhesion qualities of the tape in a reliable and repeatable manner.
As one representative example, adhesive tape has begun to be commonly used to secure and restrain cargo during transport in shipping containers to prevent shifting movement and attendant damage to the cargo, the container, and/or the ambient environment. An example of such a cargo restraint system is the “TY-GARD 2000”® system produced by Walnut Industries, Inc., of Bensalem, Pa., which is particularly designed and intended for use in standard shipping containers as are commonly used for ocean, rail and truck transportation of cargo. Basically, the “TY-GARD 2000” system utilizes an elongate adhesive tape formed in a relatively large width (e.g., about 16 inches) of a plastic substrate including lengthwise-extending glass fibers backed with an adhesive composition, whereby two lengths of the tape may be secured adhesively to opposite interior side walls of a shipping container and then free ends of the two tape lengths secured together across the widthwise extent of the container, e.g., via a connecting “patch” of an additional length of tape overlapping the two free tape ends, to surround and secure a unit of cargo, e.g., a shipping pallet, against movement during shipment.
As will be recognized, the effectiveness of such a cargo restraint system is directly dependent upon the strength of adhesion of the tape to the sidewalls of the container and, since cargo can vary from drums of hazardous chemicals to complex electronic equipment to delicate breakables, it is critical that the adhesion qualities of the tape be reliably testable and measurable. Heretofore, however, the testing of such cargo restraint tapes has been extremely crude and primitive, e.g., by merely adhering a length of tape to a vertical surface, attaching a designated weight to a free end of the tape, and dropping the weight under the force of gravity to exert an impact stress upon the tape. As is apparent, while such a test may be of some indication of the reliability and effectiveness of a tape, the test lacks suitable controls for the test parameters to be precisely repeatable from one test to another and the results of tests cannot be quantitatively measured and compared. Accordingly, a significant need exists for testing apparatus and methodology by which test parameters can be precisely controlled and repeated and test results can be precisely measured.